small airplane like, light, all of a sudden turn hugh and then speed off like a shooting star.

It appeared to be an airplane.It looked like a star/ airplane lights- just the main ones, not the collored lights. I saw it in the sky to my left going east on hwy110. It got really bright as if it was coming my direction. All of a sudden it "blew up" to approximately 10-20 times the size. A second later it speed off to the right (going south) really fast. It was really high in the sky, I think. It at first looked like a comet, but I would have heard of it, they don't come that close to earth, and when it speed of it apeared to be a shooting star. I think it had a greenish tint to it when it moved, not when it "exploded" though. It all happened sort of fast, but I can not explain it. I have saw another ufo a year or so ago, but I did not report it. But I would really like to know if any one else saw it/ what it is.